1. Field of the Invention
The present invention relates to a blower for a vehicle, and more particularly, to a blower for a vehicle, which has an auxiliary door formed on the upper end portion of a filter cover to open and close an indoor air inlet, thereby improving a heating performance by allowing some of the indoor air to flow therein in an outdoor air inflow mode regardless of the type (a plate type, a dome type, or others) of an indoor and outdoor air switching door as well as improving productivity and reducing manufacturing costs since an installation and a configuration are simple.
2. Background Art
In general, an air conditioner for a vehicle is designed to introduce indoor/outdoor air of the vehicle thereto and heat or cool it so that the heated or cooled air is blown into the interior of the vehicle, thereby to heat or cool the interior of the vehicle.
As shown in FIG. 1, the air conditioner includes: a blower 10 having an indoor air inlet 21 and an outdoor air inlet 22 formed at a side thereof, an indoor and outdoor air switching door 23 for selectively opening and closing the indoor air inlet 21 and the outdoor air inlet 22, and a blower fan 35 for forcedly blowing the indoor air and the outdoor air toward an inlet 43 of an air-conditioning case 40; and the air-conditioning case 40 having the inlet 43 for introducing the air blown from the blower 10 and an outlet 44 for discharging the air, the air-conditioning case 40 in which an evaporator 41 and a heater core 42 are mounted in order in such manner as to be spaced apart from each other by a predetermined interval.
Here, the indoor and outdoor air switching door 23 adopts one of various types, for instance, a plate type, a dome type to which pressure of the air is applied a little, a cylindrical type, a hemispherical type, and so on according to the use purpose.
FIG. 2 is a sectional view showing a general blower for a vehicle to which the plate-type indoor and outdoor air switching door is applied. As shown in FIG. 2, the blower 10 includes: an intake duct 20 having an indoor air inlet 21 and an outdoor air inlet 22 for respectively introducing the indoor air and the outdoor air and an indoor and outdoor air switching door 23 mounted therein for selectively opening and closing the indoor air inlet 21 and the outdoor air inlet 22; a scroll case 30 coupled to the lower portion of the intake duct 20 and having a blower fan 35 for forcedly blowing the indoor air and the outdoor air to the inside of the air-conditioning case 40; an air filter 25 detachably mounted between the intake duct 20 and the scroll case 30 and having a filter portion 26 and a frame portion 27 for filtering impurities in the introduced air; and a motor 36 mounted below the scroll case 30 to operate the blower fan 35.
In addition, the indoor and outdoor air switching door 23 is actuated by a cable (not shown) and an actuator (not shown), which are mounted separately.
So, the indoor and outdoor air switching door 23 opens the indoor air inlet 21 and closes the outdoor air inlet 22 in an indoor air introducing mode, and in this instance, the indoor air introduced through the indoor air inlet 21 by the actuation of the blower fan 35 passes through a bell mouth 31, moves to the scroll case 30, and then forcedly sent to the inside of the air-conditioning case 40.
Moreover, on the contrary, the indoor and outdoor air switching door 23 closes the indoor air inlet 21 and opens the outdoor air inlet 22 in an outdoor air inflow mode, and in this instance, the outdoor air introduced through the outdoor air inlet 22 by the actuation of the blower fan 35 passes through a bell mouth 31, moves to the scroll case 30, and then forcedly sent to the inside of the air-conditioning case 40.
However, the blower 10 according to the prior art needs a great deal of driving power to enhance a heating performance when a heater is turned on in the winter season or cold days. That is, a driver sets the outdoor air inflow mode to keep a heated state of the vehicle and prevent frost formed on a window in the winter season, and thereby only a cold outdoor air is introduced through the outdoor air inlet 22. So, the blower 10 according to the prior art needs much driving power necessary for heating the inside of the vehicle and deteriorates the heating performance.
To solve the above problems, Japanese Utility Model Laid-Open Publication No. So57-76120 discloses a blower, which has an improved indoor and outdoor air switching door to introduce some of the indoor air in the outdoor air inflow mode, thereby improving a heating performance.
FIG. 3 is a partially sectional view of a blower according to a prior art, and FIG. 4 is a perspective view of an indoor and outdoor air switching door of FIG. 3. The blower includes a plate-type indoor and outdoor air switching door 63 rotatably mounted between an indoor air inlet 61 and an outdoor air inlet 62 for selectively opening and closing the indoor air inlet 61 and the outdoor air inlet 62, the indoor and outdoor air switching door 63 having an auxiliary passageway 71 formed on the upper portion thereof and an auxiliary door 70 formed on a rotary shaft 63a thereof for opening and closing the auxiliary passageway 71 while freely moving on the center of the upper end thereof.
That is, the auxiliary door 70 is usually in a state to close the auxiliary passageway 71 by self-weight, but actuated to open the auxiliary passageway 71 by a negative pressure (pressure difference) generated by an actuation of the blower fan (now shown) in the outdoor air inflow mode. Therefore, when the heater is turned on, the outdoor air introduced through the outdoor air inlet 62 and the indoor air introduced through the auxiliary passageway 71 are mixed and introduced to the inside of the air-conditioning case to thereby reduce driving power necessary for heating and improve the heating performance.
However, since the upper end portion of the indoor and outdoor air switching door 63 is fixed to the rotary shaft 63a using separate fixing screws 64 after the auxiliary door 70 is assembled to the rotary shaft 63a of the indoor and outdoor air switching door 63 in a flap form to individually rotate the indoor and outdoor air switching door 63 and the auxiliary door 70, the blower according to the prior art has several problems in that the number of components is increased unnecessarily, assembling work is complicated, and productivity is lowered due to a rise of manufacturing costs.
In addition, as described above, since the indoor air introducing structure using the auxiliary door 70 in the outdoor air inflow mode can be applied only to the plate-type indoor and outdoor air switching door 63 but cannot be applied to the dome-type or other type (cylindrical type, hemispherical type) indoor and outdoor air switching door, the indoor air cannot be introduced in the outdoor air inflow mode, and thereby, the heating performance is deteriorated.